Optical instrument



OPTICAL INSTRUMENT Filed Sept. 21', 1944 BERNARD J. WOLFE 3m entor B5 @XMQ (Tttorneg Patented ay 7, 1946 or'rrcAL INSTRUMENT Bernard J. Wolfe, Irondequoit, N. Y., assisnor to Bausch & Lomb Optical Company, Rochester, N. Y., a corporation of New York Application September 21, 1944, semi No. 555,104

4, Claims.

This invention relates to optical instruments and more particularly it has reference to desiccating devices which are used in optical instruments to absorb moisture which might otherwise impair the performance of the instrument.

One of the objects of the invention is to provide an improved means for holding the desiccating device in the instrument. Further objects are to provide a de'siccating device which can be readily secured to existing types of instruments and embodies means for holding the device in spaced-relation to the surface of the prism. These and other objects and advantages reside in certain novel features of construction, arrangement, and combination of parts as will hereinafter be more fully described and pointed out in the appended claims.

Referring to the drawing:

Fig. 1 is a view of a binocular body tube, with parts broken away to show the application of my invention.

Fig. 2 is a side view of my desiccating device in position on a prism support.

Fig. a is a top plan view of same.

Fig. 4 is a sectional view taken on line 4-4 of his. 3.

Fig. 5 is a sectionalviewtaken on line 5-5 of A preferred embodiment of my invention is disclosed in the drawing wherein I have shown the invention as applied to a binocular comprising the body tube it within which is carried a shelf it for supporting the prisms I2 and I3. The prism 62 is secured to theshelf H by means of theposts it and it which are secured to the shelf M. The prism it is located on the shelf It by means of a collar it, or other suitable device, secured to the shelf it by screws 11. A resilient yoke it engages the top of prism l2 and has its ends secured, respectivelyto the posts It and I5 by means of screws it and 2h.

The desiccating device 2i comprises a boxliire structure having a top wall 22, and an inclined side 23 which is spaced from and substantially parallel to the face 2! of the prism 12. The device at has a perforated wall 25 against the inner side of which is placed a sheet of filter paper it so as to prevent the desiccating material 21 from passing through the apertures. The device H is preferably formed of a molded plastic material and the desiccating material 21 may be any suitable substance, such as, silica gel.

The top wall 22 of the device 2| has on its under Y surface recess portions 28 and 28 which are adapted to rest, respectively, upon the screws I! and 20 carried'by the posts I and IS. The top wall 22 is provided with a slot 30 through which the member I8 extends. The lower side of the device 2| carries an integral depending foot 3| which is adapted to rest on the top of the shelf I I when the device is in place in the instrument. The top wall 22 of the device 2! carries a spring member 32 which is adapted to engage the under' side of cover 33 which encloses the body tube Hi. It will be apparent, therefore, that when the cover 33 is in place, the desiccating device 2| is yieldably held in position by means of the spring .32. The desiccating device 2| may be readily removed by merely lifting it of! of its supporting members after the cover 33 has been removed. When the device is in position, it does not contact the reflecting face of the prism and so is not apt to scratch the polished surface and thereby caus impairment of the instrument.

From the foregoing, it will be apparent that I am able to attain the objects of my invention and provide a. desiccating device which may be readily applied to or removed from the instrument. The device is firmly held in position and is so constructed that it does not contactthe polished face of the prism. Various modifications may obviously be made without departing from the spirit of my invention.

I claim;

1. In an optical instrument having a support, a prism mounted on the support, and means for holding said prism to the support, including a pair of spaced posts secured to the support, the

combination of a desiccating device mounted in spaced relation to a surface of the prism and means for holding the desiccating device comprising recessed portions on the device which fit over the ends of said posts and a foot member on the device which rests on said support.

2. In an optical instrument, the combination of a casing, a support mounted within the casing and carrying a prism having an inclined face, means for holding the prism to the support comprising a pair of posts secured to the support on opposite sides of the prism, a desiccating device and means for holding the device in spaced relation to said inclined face, said last-named means comprising recessed portions on the device which 3. In an optical instrument, the combination of a support carrying a prism having an inclined face, a desiccating device having an inclined side, and means for supporting the device with its inclined side spaced from and substantially peraliel to the inclined face of the prism, said means comprising two spaced members carried by the support and a foot extending downwardly from the device, spaced portions of the device being supported by the members and the foot being carried by the support.

i. In an optical instrument having a. prism with an inclined face, the combination of e. cesing, a, support mounted within the casing and carrying the prism. n desicceting device having a top well end an inciined side, said device being mounted with its inclined side spaced from and substantially parallel to said face, and means for holding said device comprising three spaced supporting portions carried by the suppo t and constructed' and arranged to engage three spaced portions on the device, resilient means carried by the top wall of the device, end e cover for said casing, said resilient means being in yieidable engegement with the cover whereby the spaced portions on the device are held in yieldable engagement with the spaced portions on the support.

ARD J. WOLFE. 

